WASHINGTON — Pentagon officials insisted Monday that the weekend's Afghanistan killing spree was an "isolated incident" and said that a 38-year-old Army staff sergeant would soon be charged in connection with the deaths of 16 Afghan civilians, including nine children.

Defense Secretary Leon Panetta, traveling to Krygzystan, said Monday evening that the soldier could face the death penalty.

"We seem to get tested almost every other day with challenges that test our leadership and our commitment to the mission that we're involved in," Panetta said, according to an Associated Press reporter traveling with him. "War is hell.

Under the Uniform Code of Military Justice, a premeditated murder conviction could carry the death penalty.

Regardless of what the soldier is charged with, defense and security experts worried Monday that the fallout from Sunday's massacre in southern Kandahar province will be anything but isolated.

In the perception of Afghans, the experts said, the rampage merely adds to previous nightmares: the recent burning of Qurans by U.S. soldiers, eight children killed in February by NATO bombs, a video of Marines urinating on corpses, and others. Each incident separately posed problems for the Obama administration's plans for an orderly end to the U.S. combat mission in Afghanistan, but the question now is whether, taken together, the incidents have made the American presence there untenable.

"The cumulative effect of these events makes it harder to climb what was already a very steep hill," said John Nagl, an expert on military counterinsurgency strategy and a professor at the U.S. Naval Academy.

The pillars of the Obama administration's plans to wind down the decade-long Afghan war seem increasingly shaky. As news of the killings sparked outrage in Afghanistan — prompting U.S. forces to beef up security precautions — it seemed increasingly unclear whether the United States could reach an agreement with the Afghan government for a long-term role for the American military, which U.S. officials are seeking to ensure that al Qaida militants don't regain safe haven there.

The incident also undermined U.S. efforts to push Taliban leaders into peace talks with the Afghan government, analysts said. As calls grow for U.S. forces to exit Afghanistan, a growing number of Afghans believe the Taliban are content to wait out the end of the American presence.

"Our strategy is based on building trust and goodwill," Nagl said. "That trust takes a long time to build and can be destroyed by events like this very quickly."

In Afghanistan, the killings fed into a narrative, promoted by the Taliban, that the U.S.-led international coalition frequently kills civilians. Afghan lawmakers condemned the shooting spree, saying that "Afghans have run out of patience with arbitrary acts of foreign forces," according to a statement by the lower house of Parliament, which canceled its session Monday in protest over the killings.

The Taliban wasted little time taking advantage of the situation, issuing a statement blasting the "sick-minded American savages."

President Barack Obama told WFTV in Orlando, Fla., that the killings were "in no way ... representative of the enormous sacrifices that our men and women have made in Afghanistan." But he added, "It does signal the importance of us transitioning in accordance with my plans that Afghans are taking more of the initiative in security."

White House Press Secretary Jay Carney said the shootings would not impact the timetable for withdrawing U.S. troops.

"We will continue to pursue our strategic objective in Afghanistan, which (is) about the U.S. national security interest and the protection of the United States, our personnel, and our allies," Carney said.

Carney did say that NATO ministers would discuss the withdrawal timetable when they meet in Chicago in May. But he stressed that the rampage would not shift the course of those talks.

"I do not believe that this incident will change the timetable of a strategy that was designed and is being implemented in a way to allow for the withdrawal of U.S. forces, to allow for the transfer of lead security authority over to the Afghans, a process that will be completed no later than the end of 2014," Carney said.

A U.S. Army official, speaking on condition of anonymity because he wasn't authorized to be quoted, said that the staff sergeant in custody would be charged by U.S. military authorities Kabul. The soldier, whose identity was being withheld pending the charges, is based at Joint Base Lewis-McChord in Washington state, officials said.

The official said that just after 1 a.m. Sunday, the soldier walked off his base in Kandahar's Panjway district. An Afghan security guard noticed him leave and notified the soldier's chain of command. Before commanders identified who was missing, the sergeant returned to the base and was immediately apprehended, the official said.

Afghan officials said that the soldier entered homes in the Belandi-Pul village and opened fire, killing 16 civilians, including three women and nine children, and wounding five more.

The U.S. official said that the sergeant is believed to have used his military-issued service weapon. So far, there are no reports of a motive.

The staff sergeant had served three tours of duty in Iraq before arriving in Afghanistan, the official said — renewing questions about the strain of multiple deployments on U.S. service members over the past decade.

Pentagon spokesman George Little called the shooting an "isolated incident," but Little has also described other recent incidents that inflamed U.S.-Afghan relations as isolated, such as the Quran burnings and the video of Marines urinating on corpses.

Anthony H. Cordesman, a defense expert at the Center for Strategic and International Studies, said that the massacre points to the need for a new Afghanistan strategy. He criticized the Obama administration for sticking with a withdrawal plan that's failing and argued that it's time to accept that the mission has failed and bring U.S. troops home, or to construct "a real transition strategy based on credible goals, credible resources, and doing things the Afghan way."

"We need to face the fact that (the massacre) only highlights the growing problem the United States faces in creating any kind of strategy for Afghanistan that can survive engagement with reality," Cordesman said.

(Steven Thomma of the Washington Bureau and McClatchy special correspondent Ali Safi in Kabul contributed.)

Join The Conversation

McClatchy Washington Bureau is pleased to provide this opportunity to share
information, experiences and observations about what's in the news.
Some of the comments may be reprinted elsewhere in the site or in the
newspaper. We encourage lively, open debate on the issues of the day,
and ask that you refrain from profanity, hate speech, personal
comments and remarks that are off point. Thank you for taking the time
to offer your thoughts.